A high-efficiency artificial-photosynthesized CdS/BiFeO3 S-scheme heterostructure with synergistically enhanced built-in electric field and stably ferromagnetic recyclability

This work explored the design of an artificial photosynthetic CdS/BiFeO 3 S-scheme heterojunction catalyst integrated with piezo-electric synergistically enhanced built-in field and ferromagnetic recyclability. A combined sol–gel and solvothermal approach achieved uniform dispersion of CdS nanoparticles on BiFeO 3 surfaces with strong interfacial coupling. Through comprehensive characterization techniques and density functional theory calculations, this innovative construction of powder catalyst facilitated wide solar-spectrum response, spatial charge separation, optimized thermodynamic potentials, and high-efficiency surface reaction. The hybrid catalyst exhibited outstanding tetracycline (TC) degradation performance under simulated sunlight irradiation, with ultrasonic treatment further enhancing the reaction kinetics. Herein, the synergistic integration of ultrasonic irradiation with photocatalysis significantly enhanced the degradation efficiency, reaching an optimal TC degradation rate of 18.01 μmol⋅g −1 ⋅min −1 . This remarkable enhancement originates from the cooperative effects between the built-in electric field of the S-scheme heterojunction and the piezoelectric field induced by ultrasound, which collectively accelerate the Fe 2+ /Fe 3+ redox cycle and significantly promote ·OH generation and transformation in the photo-Fenton process. Our findings provide insights for the rational design of ferroelectric catalyst to harness synergistic effect in artificial photosynthetic system.